Sonar systems, such as sonar depth finders and sonar fish finders, are commonly employed by boaters and sport fishermen. These sonar systems are based upon sonar systems developed during the World War II era which generated a sonar signal that was transmitted through a body of water and reflected by the bottom surface of the body of water to the sonar system. Based upon the length of time between the generation of the sonar signal and the reception of the reflected signal by the sonar system, these sonar systems could determine the distance to the bottom surface of the body of water.
Based on these early sonar systems, a number of sonar systems have been developed which display the reflected sonar signals in a variety of manners. For example, some sonar systems include rotating disk lamps or "flashers" which produce a pulse of light upon the reception of a reflected sonar signal. However, flashers do not generally provide historical data representative of the contour of the bottom surface of the body of water. Instead, the pulse of light provides only a momentary indication of the distance to the bottom surface of the body of water. Accordingly, the operator must closely monitor the flasher in order to determine the contour of the bottom surface of the body of water. In addition, sonar signals reflected by submerged objects, such as fish, are typically difficult to identify by the pulses of light provided by flashers since the pulses of light provide only a momentary indication of the distance to the submerged object from which the sonar signals are reflected.
In order to provide historical data indicative of the contour of the bottom surface of the body of water as well as the relative location of submerged objects, such as fish, sonar systems were developed which included a chart recorder. These sonar systems generate a strip chart on which markings indicate the contour of the bottom surface of the body of water as determined from the reflected sonar signals. While sonar systems incorporating chart recorders provide a permanent record of the contour of the bottom surface of the body of water, the strip charts produced by these sonar systems can be relatively difficult to interpret.
For example, the strip charts typically include a wide area or band of markings to indicate the relative location of the bottom surface of the body of water. However, thermoclines within the body of water or multiple reflections of the sonar signals, such as due to spurious reflections of the sonar signals from the bottom surface of the boat, can create additional reflections which, if received by the sonar system, will create additional lines or bands on the strip chart. In addition, the operator of a sonar system having a chart recorder may change the scale to which the strip chart is drawn in order to more clearly depict the bottom surface of a body of water. However, the strip chart generated prior to the change in scale will remain drawn to the previous, albeit different, scale. Thus, the operator of the sonar system may find it difficult to read and compare markings on the strip chart, particularly in the region in which the scale of the strip chart was changed.
Accordingly, sonar systems having associated display devices have been developed to provide a historical display of the bottom surface of the body of water over which the boat is passing as well as to identify submerged objects from which the sonar signals reflect. The associated display devices typically include cathode ray tubes, electroluminescent panels, liquid crystal displays and LED displays. These sonar systems also generally include advanced electrical circuitry, including one or more microprocessors or microcontrollers, to provide a number of features which allow the operator to customize the resulting display.
For example, U.S. Pat. No. 5,184,330 to James W. Adams et al. which issued Feb. 2, 1993 describes a sonar fish detection apparatus which provides a three-dimensional (3D) wire-frame display of the contour of the bottom surface of the body of water as well as submerged objects from which the sonar signals reflect. As illustrated in FIGS. 16-21, the sonar fish detection apparatus of the Adams '330 patent includes a number of display features which the operator can selectively activate. For example, the operator can increase or decrease the sensitivity of the sonar fish detection apparatus. The operator can also choose to display the speed of the boat on which the sonar fish detection apparatus is mounted. Still further, the operator can activate or deactivate both the fish alarm and the bottom alarm. The sonar fish detection apparatus of the Adams '330 patent also allows the operator to select the type of display which is generated. For example, the operator can select a three-quarters view, a straight-on view, or a side view.
In addition to providing displays which have a number of operator-selectable features as described above, sonar systems have also been developed which include a number of transducers for more accurately depicting the contour of the bottom surface of a body of water as well as objects submerged therein. For example, U.S. Pat. No. 4,879,697 to Darrell J. Lowrance, et al. which issued Nov. 7, 1989 and is assigned to the Lowrance Electronics, Inc. describes a sonar fish finder apparatus which includes three transducers. As shown in FIG. 4 of the Lowrance '697 patent, each transducer is mounted to emit sound waves in a generally conical beam which is directed in a predetermined orientation. The predetermined orientations in which the sound waves generated by each transducer are directed preferably extend in three different directions such that the sonar system can effectively map a relatively large portion of the bottom surface of the body of water.
In addition to being oriented in different directions, the sound waves generated by sonar transducers can have a variety of other signal characteristics. These signal characteristics can vary from transducer to transducer. For example, the cone angle and the frequency of the sonar signals emitted by the transducers can differ. Accordingly, the operator of a sonar system having multiple transducers can selectively activate predetermined ones of the transducers in order to optimize the resulting display. For example, the operator can selectively activate the transducers which emit sound waves oriented in a predetermined direction, such as a direction which is of particular interest to the operator. Alternatively, the operator may selectively activate the transducers having a cone angle and/or a frequency which is best suited for locating submerged objects, such as fish, at a predetermined depth or range of depths within the body of water. Accordingly, the operator can effectively optimize the performance of the sonar system based upon the selective activation of one or more transducers which emit sonar signals having the desired signal characteristics.
As described heretofore, sonar systems have been developed which produce historical displays of the contour of the bottom surface of the body of water over which the boat is passing as well as objects suspended therein. These sonar systems can include displays having a number of features which can be selected based upon the operator's display preferences. In addition, these sonar systems can include multiple transducers which can be selectively activated to optimize the performance of the sonar system.
While the increased number of operator-selectable features and options provided by conventional sonar systems increase the flexibility and can improve the performance of the sonar system, the selection and initiation of the features and options can complicate the process by which the operator configures and activates the sonar system. For example, in order to selectively activate the appropriate transducers and to configure the resulting display as desired, the operator of a conventional sonar system must be very knowledgeable and experienced in the operation of the sonar system in order to remember the sequence of steps required to appropriately configure the sonar system. Alternatively, an operator of a conventional sonar system must refer, oftentimes repeatedly, to a manual or to a textual or graphical screen display provided to the operator which describes the sequence of steps required to appropriately configure the sonar system, but which are typically cluttered with superfluous or extaneous information, thereby making it relatively difficult for the operator to appropriately configure the sonar system. As will be apparent, it is possible that the relatively complicated procedure required to selectively configure conventional sonar systems will decrease the number of operators who attempt to selectively configure the sonar system since such configuration can be time consuming and, in many instances, frustrating.